SANITARY SEWER OVERFLOW EVALUATION REPORT

S

ANITARY

S

EWER

O

VERFLOW

E

VALUATION

R

EPORT

MAY

2012

– SEPT

2013

Prepared by: James C. Hailey & Company

Draft for Review: November 13, 2013

City of Gallatin, Sumner County, TN Sanitary Sewer Collection Evaluation Report 2013

i

Sanitary Sewer Collection System

Corrective Action Plan/ Engineering Report

Table of Contents

Report Summary…....………..……….…..

1

Sanitary Sewer Overflow Report……….

2

Chronic Overflow Evaluation……….………

5

Woodvale Pump Station……….

5

Stephanie

Street……….……….

5

Number 1 Pump Station ……….

5

Bulls Creek Pump Station...……….

6

Isolated Overflows………..

7

Minor Overflows……….……….

7

City

of

Gallatin,

Sumner

County,

TN

Sanitary

Sewer

Overflow

Evaluation

Report

1

Report

Summary

In

May

2012,

an

Agreed

Order

between

the

Tennessee

Department

of

Environment

and

Conservation

and

The

City

of

Gallatin

became

effective.

As

part

of

the

Agreed

Order

Gallatin

Public

Utilities

(GPU)

agreed

to

submit

a

Sanitary

Sewer

Overflow

Evaluation

Report

annually.

This

report

encompasses

a

summary

of

the

documented

overflows

beginning

at

the

date

of

the

Agreed

Order,

May

2012,

thru

September

2013.

The

accompanying

spreadsheet

documents

each

overflow

that

has

been

recorded

over

the

last

16

months.

The

report

analyzes

the

cause

of

each

overflow

and

identifies

the

measures

needed

to

identify

and/or

correct

the

overflow.

The

Table

Key

is

as

follows:

Basin: 

The

City

of

Gallatin

is

divided

into

three

drainage

basins

separated

by

topography

or

system

configuration.

Location:   

Identified

as

the

manhole,

pump

station,

address,

etc.

where

the

actual

overflow

event

occurred.

Beginning

Date:  

Identifies

on

what

calendar

day

the

overflow

started

End

Date:  

Identifies

on

what

calendar

day

the

overflow

ended.

Duration:  

Details

the

total

length

of

time

that

the

overflow

occurred.

Overflow

Cause:   

Identifies

that

cause

of

the

overflow

event,

i.e.

rainfall,

mechanical

failure,

etc.

Remarks:   

Identifies

any

specific

notes

related

to

the

overflow

event.

Rainfall

totals,

specific

system

problems,

actions

taken,

etc.

specific

to

any

given

event.

Long

Term

Capital

Plan:  

This

section

identifies

each

overflow

location

and

where

each

stands

in

regards

to

GPU

and

current

and/or

future

capital

improvements.



N/A 

–

Isolated

incident



Complete

d

–

A

current

project

has

been

completed

to

rectify

the

overflow

situation



Under

Construction 

–

A

current

construction

project

is

underway

to

improve

the

Inflow

and

Infiltration



Current

Five

Year

Plan 

–

These

events

have

projects

that

are

currently

in

the

Planning

and

Design

phase.



Under

Review 

–

These

events

are

under

review

to

determine

what

if/any

improvements

are

needed

to

correct

the

issues.

BASIN OVERFLOW LOCATION BEG DATE END DATE DURATION OVERFLOW CAUSE REMARKS Long Term Capital Plan

C Hoeganaes Lift Station 9/25/2013 9/25/2013 .50 Hours Mechanical Failure Float Failure N/A

A Across from 900 Aqua Dr 9/9/2013 9/9/2013 4 Hours Mechanical Failure Replace Air Release Valve Completed - ARV was replaced

A Across from 900 Aqua Dr 9/6/2013 9/6/2013 2.25 Hours Mechanical Failure Air Release Valve N/A

A Number One Lift Station 8/12/2013 8/12/2013 4.5 Hours Rainfall 1.3 + Inches Current Five Year Plan - Looking at a capital investment for system Improvements

C Bulls Creek Lift Station 8/12/2013 8/12/2013 5 Hours Rainfall 1.3 + Inches Current Five Year Plan - Looking at a capital investment for upgrades

B Lakeshore Dr Lift Station 8/8/2013 8/9/2013 17.75 Hours Rainfall 4.5 + Inches Under Construction - Current Rehabilitation Project to reduce Inflow

C Bulls Creek Lift Station 8/8/2013 8/8/2013 7 Hours Rainfall 4.5 + Inches Current Five Year Plan - Looking at a capital investment for upgrades

A Number 1 Lift Station 8/8/2013 8/8/2013 14 Hours Rainfall 4.5 + Inches Current Five Year Plan - Looking at a capital investment for system Improvements

C Cairo Rd Lift Station 8/8/2013 8/8/2013 .5 Hours Mechanical Failure Under Review

A Manhole #A17-M1 8/8/2013 8/8/2013 .5 Hours Rainfall 4.5 + Inches N/A - However a Current Rehabilitation Project will also reduce Inflow at this location

C Bulls Creek Lift Station 7/30/2013 7/30/2013 .75 Hours Mechanical Failure Current Five Year Plan - Looking at a capital investment for upgrades

C 1830 Woods Ferry Rd 7/29/2013 7/29/2013 2.5 Hours Damaged Force Main N/A

C Bulls Creek Lift Station 7/29/2013 7/29/2013 5 Hours Damaged Force Main N/A - Not related to flow

A Manhole #A19-C01 7/27/2013 7/27/2013 .75 Hours Blockage N/A

C Baywatch Lift Station 5/14/2013 5/14/2013 4.7 Hours Excess Flow N/A

C Cairo Rd Lift Station 5/9/2013 5/9/2013 .25 Hours Mechanical Failure Under Review

A Manhole #A02-A08 5/6/2013 5/6/2013 .5 Hours Blockage N/A

A Number 1 Lift Station 5/5/2013 5/5/2013 16 Hours Rainfall 3+ Inches Current Five Year Plan - Looking at a capital investment for system Improvements

C Bulls Creek Lift Station 5/4/2013 5/5/2013 8.5 Hours Rainfall Current Five Year Plan - Looking at a capital investment for upgrades

A Manhole #A10A-A13 5/5/2013 5/5/2013 19 Hours Rainfall Under Construction - Current Rehabilitation Project to reduce

Inflow

A Number 1 Lift Station 4/27/2013 4/29/2013 39 Hours Rainfall 5+ Inches Current Five Year Plan - Looking at a capital investment for system Improvements

C Bulls Creek Lift Station 4/27/2013 4/28/2013 28.5 Hours Rainfall 5+ Inches Current Five Year Plan - Looking at a capital investment for upgrades

B Lakeshore Drive Lift Station 4/27/2013 4/29/2013 49.5 Hours Rainfall 5+ Inches Under Construction - Current Rehabilitation Project to reduce Inflow

C Cairo Lift Station 4/27/2013 4/28/2013 2 Hours Rainfall 5+ Inches Under Review

A Manhole #A10A-A13 4/27/2013 0429-13 59.25 Hours Rainfall 5+ Inches Under Construction - Current Rehabilitation Project to reduce Inflow

BASIN OVERFLOW LOCATION BEG DATE END DATE DURATION OVERFLOW CAUSE REMARKS Long Term Capital Plan

A Manhole #A10A-N1 4/27/2013 4/29/2013 42.25 Hours Rainfall 5+ Inches Under Construction - Current Rehabilitation Project to reduce Inflow

A Manhole #A10A-PB1 4/27/2013 4/29/2013 42.25 Hours Rainfall 5+ Inches Under Construction - Current Rehabilitation Project to reduce Inflow

A Manhole #A19-B02 4/27/2013 4/28/2013 28.5 Hours Rainfall 5+ Inches Under Construction - Current Rehabilitation Project to reduce Inflow

A Manhole #A19-B03 4/27/2013 4/29/2013 42 Hours Rainfall 5+ Inches Under Construction - Current Rehabilitation Project to reduce Inflow

A Manhole #TA1 4/27/2013 4/28/2013 23 Hours Rainfall 5+ Inches N/A - However the current Five year plan will make

improvements that will affect this location A Number 1 Pump Station 4/11/2013 4/11/2013 4 Hours Mechanical Failure & Rainfall Current Five Year Plan - Looking at a capital investment for

system Improvements

B Manhole #B2-F03 3/9/2013 3/9/2013 1.75 Hours Blockage N/A

C Manhole #C12-A6 2/6/2013 2/6/2013 1 Hour Blockage N/A

A Number 1 Lift Station 1/30/2013 1/30/2013 4.25 Hours Rainfall Current Five Year Plan - Looking at a capital investment for system Improvements

A Manhole #A10A-PB1 1/30/2013 1/30/2013 0.75 Hours Rainfall Under Construction - Current Rehabilitation Project to reduce

Inflow

A Manhole #A10A-A13 1/30/2013 1/30/2013 12 Hours Rainfall Under Construction - Current Rehabilitation Project to reduce

Inflow

C Woodvale Lift Station 1/30/2013 1/30/2013 16 Hours Rainfall Completed - New station placed into service March of 2013

A Manhole #A10A-A13 1/13/2013 1/17/2013 104 Hours Rainfall Under Construction - Current Rehabilitation Project to reduce

Inflow

C Woodvale Lift Station 1/13/2013 1/17/2013 95.5 Hours Rainfall Replacement Under

Construction Completed - New station placed into service March of 2013

A Number 1 Lift Station 1/13/2013 1/14/2013 30 Hours Rainfall Current Five Year Plan - Looking at a capital investment for

system Improvements

B Lakeshore Dr Lift Station 1/13/2013 1/14/2013 19 Hours Rainfall Under Construction - Current Rehabilitation Project to reduce Inflow

A Manhole #TA-36 1/13/2013 1/14/2013 16 Hours Rainfall Under Construction - Current Rehabilitation Project to reduce

Inflow

A Manhole #A19-B3 1/13/2013 1/14/2013 16 Hours Rainfall Under Construction - Current Rehabilitation Project to reduce

Inflow

B Manhole #B15-A17 1/13/2013 1/14/2013 16 Hours Rainfall N/A

A Manhole #A23-J3 1/13/2013 1/14/2013 12.5 Hours Rainfall N/A

A Manhole #A10-A-PB1 1/13/2013 1/14/2013 22.5 Hours Rainfall Under Construction - Current Rehabilitation Project to reduce

Inflow

B 1059 Browns Ln 1/2/2013 1/2/2013 20 Minutes Mechanical Failure N/A

C Woodvale Lift Station 12/10/2012 12/10/2012 5 Hours Rainfall Completed - New station placed into service March of 2013

B LH Pk @ Buckingham Blvd 9/26/2012 9/27/2012 19 Hours Excavation Damage N/A

BASIN OVERFLOW LOCATION BEG DATE END DATE DURATION OVERFLOW CAUSE REMARKS Long Term Capital Plan

C Woodvale Lift Station 9/8/2012 9/8/2012 5 Hours Rainfall Completed - New station placed into service March of 2013

C Woodvale Lift Station 8/17/2012 8/17/2012 9.5 Hours Rainfall Completed - New station placed into service March of 2013

C Woodvale Lift Station 8/9/2012 8/9/2012 3.5 Hours Rainfall Completed - New station placed into service March of 2013

C Woodvale Lift Station 7/20/2012 7/20/2012 12 Hours Rainfall Completed - New station placed into service March of 2013

C Cairo Road Lift Station 7/19/2012 7/20/2012 3.5 Hours CEMC Power Failure Current Five Year Plan - Looking at a capital investment for a backup Generator

C Manhole C15-A02/

Steam Plant Lift Station 7/11/2012 7/11/2012 2 Hours Vandalization Copper Wire stolen N/A

C Woodvale Lift Station 7/6/2013 7/6/2013 3 Hours Power Outage Completed - New station placed into service March of 2013

A Number 1 Lift Station 5/13/2012 5/14/2012 26 Hours Rainfall Event Current Five Year Plan - Looking at a capital investment for system Improvements

C Woodvale Lift Station 5/13/2012 5/15/2012 40 Hours Rainfall Event Completed - New station placed into service March of 2013

B Lake Shore Lift Station 5/13/2012 5/14712 9 Hours Rainfall Event Under Construction - Current Rehabilitation Project to reduce Inflow

City

of

Gallatin,

Sumner

County,

TN

Sanitary

Sewer

Overflow

Evaluation

Report

5

Chronic

Overflow

Evaluation

A

chronic

overflow

for

the

purposes

of

this

report

are

those

that

make

up

more

than

10%

of

the

total

documented

overflows

for

the

review

period.

The

4

locations

listed

below

represent

~52%

of

total

documented

overflows

for

the

review

period.

Woodvale

Lifts

Station

The

most

chronic

and

cumbersome

overflow

location

for

several

years

was

the

Woodvale

Sewer

Lift

Station.

As

outlined

in

the

Overflow

report,

this

station

made

up

17%

of

the

documented

overflows

from

the

date

of

the

order

to

9/25/13

and

represented

the

largest

single

point

discharge.

All

in

past

tense

as

a

construction

project

completed

in

March

of

this

year

eliminated

this

overflow

point

from

the

system.

The

new

station

includes

two

625

gpm

pumps,

variable

frequency

drives,

a

natural

gas

backup

generator,

and

other

amenities

which

have

corrected

the

earlier

problem

and

will

now

handle

the

capacity

of

the

drainage

in

which

it

is

located

for

the

foreseeable

future.

Stephanie

Street

Manholes

A10A

‐

A13,

A10A

‐

N1

and

A10A

‐

PB1

are

all

three

located

along

a

short

stretch

of

Stephanie

Street

and

these

three

locations

account

for

13%

of

the

current

documented

overflows.

This

area

has

been

a

chronic

overflow

location

and

has

been

posted

for

several

years.

The

lines

had

been

jetted

and

TV’d

and

review

had

revealed

that

there

was

some

problems

with

line

size

vs

capacity

as

well

as

one

section

of

line

that

had

a

significant

obstruction

that

caused

surcharging

and

overflows

above

the

section

The

last

documented

overflow

of

these

three

location

was

May

of

this

year,

soon

after

a

current

rehabilitation

project

replaced

the

section

of

line

that

was

in

question

and

replaced

it

with

a

new

HDPE

line.

The

installation

of

the

new

HDPE

line

has

eliminated

the

overflows

at

these

locations.

Number

1

Lift

Station

Number

1

Lift

station

is

the

primary

pump

station

that

transports

the

collected

sewer

of

“A”

Basin,

in

its

entirety

to

the

Wastewater

Treatment

Plant

which

accounts

for

approximately

85%

of

the

total

flow

on

the

system.

Number

1,

as

it

is

referred

to,

currently

has

two

8,500

GPM

pumps

which

are

connected

to

a

pair

of

force

mains.

Currently

Number

1

and

its

overflow

problem

are

under

review.

The

construction

of

the

Woodvale

lift

station

and

new

force

main,

removed

a

sizable

load

from

the

“A”

basin

and

Number

1,

and

the

current

rehabilitation

project

is

making

significant

strides

in

targeted

Inflow

reduction.

Upon

completion

of

the

current

project

we

intend

to

monitor

Number

1

for

overflows.

As

rehabilitation

projects

continues

to

chip

away

at

the

I

‐

N

‐

I

problems,

there

are

preliminary

discussions

of

construction

of

some

equalization

tankage

or

other

peak

storage

measures

that

would

be

used

to

clip

the

peaks

and

City

of

Gallatin,

Sumner

County,

TN

Sanitary

Sewer

Overflow

Evaluation

Report

6

allow

for

better

control

of

the

overflows

at

Number

1.

There

have

not

been

any

final

decisions

made

as

to

how

best

control

these

peaks,

but

as

outlined

in

the

Collection

system

CAP

‐

ER,

the

city

is

committed

to

reducing

the

running

average

of

the

peak

flows

below

10,000

gpm

within

the

next

5

years.

Bulls

Creek

Bulls

Creek

is

the

last

of

the

“chronic”

overflow

locations

for

the

review

period,

making

up

10%

of

the

current

documented

overflows.

Bulls

Creek

was

on

the

radar,

but

did

not

become

a

“chronich”

offender

until

earlier

this

year.

As

the

primary

pump

station

for

“C”

Basin,

the

overflows

started

soon

after

the

New

Woodvale

station

went

on

‐

line.

The

new

Woodvale

station

took

its

capacity

off

of

“A”

basin

and

Number

1

and

shifted

that

flow

to

“C”

basin

and

Bulls

Creek.

It

should

be

noted

that

a

couple

of

the

overflows

were

the

result

of

mechanical

failures,

however,

that

coupled

with

the

additional

flows

it

is

currently

seeing

have

move

it

up

on

the

“To

‐

Do”

list.

The

collection

system

CAP

‐

ER

indicated

that

a

thorough

evaluation

of

the

Bulls

Creek

options

would

be

performed

within

3

years

of

the

completion

of

the

Woodvale

lift

station,

however,

given

that

the

number

of

Overflows

has

increased,

the

City

has

moved

this

up

and

Bulls

Creek

is

currently

under

review

for

needed

improvements

to

control

the

number

of

annual

overflows.

City

of

Gallatin,

Sumner

County,

TN

Sanitary

Sewer

Overflow

Evaluation

Report

7

Isolated

Overflows

Isolated

incidents,

denoted

with

an

N/A

on

the

Report,

make

up

right

at

25%

of

the

total

documented

overflows.

These

incidents

are

generally

the

result

of

a

mechanical

failure,

damaged

infrastructure,

or

other

freak

incidents

resulting

in

a

reported

overflow.

Over

the

16

months

outlined

in

the

report,

the

events

labeled

as

isolated

were

just

that,

Isolated,

occurring

only

once

over

during

the

review

period.

These

isolated

incidents

were

corrected

by

a

mechanical

repair,

line

cleaning

or

other

readily

achievable

measure

which

resulted

in

the

overflow

not

repeating.

Minor

Overflows

The

remaining

20%

of

overflows

have

been

categorized

as

minor,

in

that

they

do

not

make

up

more

than

10%

of

the

overflows.

The

Cairo

Rd

Pump

Station

has

4

of

the

reported

overflows

and

the

reasoning

varies

from

1

Power

failure,

2

mechanical

failures

and

1

rainfall

event.

The

Cario

Road

Lift

station

was

identified

within

the

CAP

‐

ER

as

a

location

that

would

be

monitored.

As

outlined

in

the

CAPER,

the

Cairo

Road

Sub

‐

Basin

is

under

review

for

I

&

I

problems

and

GPU

has

plans

to

purchase

and

install

a

back

‐

up

Generator

for

this

location

to

help

with

the

inconsistent

power

feed

issues.

The

Lakeshore

Drive

Pump

Station

has

4

reported

overflows

during

the

review

period,

all

of

which

are

the

direct

result

of

a

rainfall

event.

This

was

recognized

prior

to

the

bidding

of

the

current

rehabilitation

project

and

a

number

of

pipe

was

added

within

the

Lakeshore

Lift

Station

sub

‐

basin

in

order

to

better

control

the

I

&

I

coming

to

this

location.

Upon

completion

of

the

rehab,

we

will

continue

to

monitor

this

location

and

will

take

further

action

as

needed.

This

station

also

has

some

age

and

is

slated

for

replacement

in

the

coming

years

as

well.

The

overflows

at

TA

‐

36

and

A19

‐

B2

and

A19

‐

B3

are

all

part

along

a

section

of

the

Main

trunk

line

that

is

to

be

replaced

as

part

of

the

current

rehabilitation

project.

These

3

sites

make

up

4

of

the

reported

overflows

during

the

current

period

of

review,

and

all

were

the

result

of

rainfall

events.

There

are

4

section

of

Trunk

Line

that

will

be

replaced,

including

one

section

that

will

be

up

‐

sized

to

match

the

upstream

and

downstream

piping.

Upon

completion

of

the

current

project,

this

area

will

continue

to

be

monitored

and

additional

action

taken

as

needed.

City

of

Gallatin,

Sumner

County,

TN

Sanitary

Sewer

Overflow

Evaluation

Report

8

Conclusions

As

par

to

the

Agreed

Order,

Gallatin

Public

Utilities

(GPU)

has

monitored

for

and

maintained

all

sanitary

sewer

overflows

(SSO)

within

the

system.

This

report

has

taken

each

overflow,

reviewed

them,

and

identified

the

appropriate

action

that

should

be

taken

to

correct.

As

this

report

has

demonstrated,

GPU

is

very

active

and

aggressive

in

the

combating

of

SSO’s

and

many

of

the

documented

overflows

over

the

16

month

review

period

have

already

been

corrected

by

a

construction

project,

or

will

be

improved

and

likely

corrected

by

a

current

construction

project.

As

with

any

system

there

are

always

going

to

be

unusual

circumstances

that

can

contribute

to

an

overflow,

and

mechanical

failures

and

system

damage

can

occur

at

any

time

and

are

hard

to

prepare

for.

However,

as

this

report

demonstrates,

GPU

has

identified

those

and

appropriate

actions

taken.

GPU

has

also

identified

the

know

and

recurring

problems,

many

of

which

are

already

being

addressed

and

those

that

are

not

being

directly

addressed

currently

have

projects

in

planning

and

design

to

correct

them

in

the

near

future.

GPU

will

continue

to

aggressively

attack

the

problems

of

I

&

I

and

will

continue

to

be

vigilant

and

proactive,

that

is

not

always

a

match

for

the

Wrath

of

Mother

Nature.